Judicious training in the use of learning strategies can be very valuable for language students. However, the notion of "strategy" is not always well defined in the literature. For pedagogic purposes strategies need to meet certain criteria: they should be problem-oriented, subject to choice among alternatives, under conscious control, clearly describable and plausibly effective. The teaching of reading skills, in particular, commonly involves strategies which are of doubtful value; this is especially the case for training in "guessing unknown words". Classification of strategies is notoriously problematic: taxonomies tend to be based on questionable psycholinguistic analyses and not well targeted pedagogically. While training in strategy use can contribute usefully to learner independence, this can be taken to unconstructive extremes; and such training is no substitute for basic language teaching.